1975 Dodge Dart Rearend Swap - Size Does Matter

Who says you can't find usable parts at salvage yards and swap meets anymore? Sure, it may be harder than it used to be, and you sure as heck won't find a 426 Hemi resting in a Road Runner in a salvage yard, but sometimes you can stumble across some parts you know you will be able to use someday.

When we started to resurrect our '75 Dart Sport, we knew it needed a lot of work, and we wanted to put the car on the road with as little money as possible. We first made it road worthy, which cost us $810. Driving it was cool, but it still didn't look cool. So we painted the wheels, added a set of tires and "dog dish/poverty" caps to our painted wheels, put an OE-style wing on the trunk lid, and an A-Body scoop on the hood. This brought our total to $1,872. Now it finally looked cool, but it really didn't sound the part. So, for an additional $2,149, it sounded the part with a V-8 swap. This brought our total to $4,021. Now I don't care who you are, building a good-looking driver for under $5,000 is tough . . . but fun.

2/22You don't need big, fancy tools to do the job. Put a jack under the framerail, take the pressure off the torsion bars, remove the ball joint nuts, and then use a simple tool like this one from American Muscle. This tool simply applies pressure to the ball joint studs and knocks them out of the spindle.

There were a few things we felt we should address, if for no other reason than safety's sake. The Sport came from the factory with 9-inch drum brakes all around, and stopping was neither quick nor pleasant-it was a planned attack of excitement, especially in traffic. There are many companies that offer disc-brake conversions, and some are even "economically" priced. But what if you just can't spend the money needed to get a new kit? There are things you can do if you're willing to spend a little time looking and some elbow grease after you find what's needed.

To do the front-end swap, you'll need the spindles from a '73-and-up A-, B-, E-, F-, J-, M-, or R-chassis disk-brake car; drum spindles don't work for an OE swap. You'll also need the rotors, calipers, and caliper brackets. There are two types of calipers: pin-mount style and slider style. Don't forget to also grab the prop valve.

We were fortunate enough to find a mid-'70s B-Body that had just been brought to the local salvage yard and were able to grab the entire disc-brake setup for $50. We simply unhooked the ball joints, cut the rubber hoses, and removed the prop valve. Some of the parts from the scavenge will not be used, but when buying new calipers, for instance, there was a $15-per-caliper core charge when we got the new ones. Having the old ones to hand in saved us $30. By the time we walked out of the local auto parts store, we had spent another $245 for a new master cylinder, bearings and seals, calipers, brake pads, rotors, and brake lines.

3/22After you remove the spindle assembly, you'll need to remove the ball joint/steering arm unless you are getting new ones. Ours are new, so we saved them.

There has been a fierce debate over the use of the later B-, F-, M-, J-, and R-Body spindle. Switching to the later B-Body spindle actually gives you more stability, as the Steering Axis Inclination (SAI) is 8 degrees as opposed to the A-Body's 7.5. If you are really interested in the entire story about brake-spindle swapping, check out Mopar Muscle's March '05 issue. Bill Reilly of Reilly Motorsports (reillymotorsports.com) scientifically proved its worth.

So now we had everything needed to handle the front end, but what were we going to do with the rear? We didn't want a big bolt-pattern wheel on the front and a small bolt pattern on the rear. Not only that, the 7 1/4 rear was already making noise from the V-8's, err maybe it was the driver's abuse. trying to find an A-Body 8 3/4 rear for cheap is not going to happen, but a possibility is finding an 8 1/4 rearend. The 8 1/4 came in a lot of A-Bodies, and unless you plan on continued racing abuse, it can serve as a good economical rearend for your driver.

Luckily, we had a friend who just happened to have an 8 1/4 that was in his way, and he offered it to us. We know what you're thinking, Like anyone is going to give ME a rear for my car. Ok, so in order to be fair, we'll say a good 8 1/4 rearend could probably be had at a swap meet for about $150.

But now a really big problem has arisen-the wheels won't fit!

10/22It's a lot easier to assemble everything on the workbench and then put the finished assembly on the car.

This was a good time to upgrade the wheel-and-tire package on the Sport, but after trying a couple of different wheel styles on the car, it was decided the steelies and "dog-dish" caps looked good on the car, and it's cheap. So we called Stockton Wheel and ordered a set of steel Mopar wheels for the rear with a 4 1/2-inch bolt pattern and a 3 3/4-inch back space. The hubcaps were another gift, but we could have stayed with the older style we had. Since we were upgrading wheels to bigger bolt patterns, we also ordered 15-inch wheels. The 14-inchers just don't seem to fill the wheelwells enough; a 15-inch wheel is almost a must on these cars.

Tires would be another issue. BFGoodrich always seems to be the choice of tire for musclecar guys, so we decided to go that route. Wheels and tires will set you back about $500, which could vary depending on your tire shop.

All-in-all, the swap took us only a weekend of our time. That includes painting and rebuilding everything that needed it. So for around $870, we made the Dart safer to drive, look better with larger wheels and tires, and improved the performance since our 8 1/4 rear has a 4.10 gear in it. So what are you waiting on; the swap is easy.